DTC P1860 GMC

Description

The A C-ECU receives the air conditioning control-related signals from the WCM-ECU via the CAN bus lines. If any of the air conditioning control-related signals from the WCM-ECU cannot be received, the diagnostic trouble code U0168 is stored. Current trouble: Connector(s) or wiring harness in the CAN bus lines between the WCM-ECU and the A C-ECU, the power supply system to the WCM-ECU, the WCM-ECU itself, or the A C-ECU may be defective. Past trouble: If DTC U0168 is stored as a past trouble, carry out diagnosis with particular emphasis on wiring and connector(s) in the CAN bus line between the A C-ECU and the WCM-ECU, and the power supply system to the WCM-ECU. If the connectors and wiring are normal, and obviously the ECU is the cause of the trouble, replace the ECU. If in